IN the long run the cable is the same whether you work it with or without a cable needle, but perhaps this reading would make more sense to you.
Slip two stitches to right needle; place next 4 stitches on cable needle in front. Transfer the two slipped stitches to left needle. Slip two stitches from cable needle to right needle and then slip those two to the left needle. Slip remaining two stitches from the cable needle to the left needle. knit the 6 stitches.